I am studying Griffith's Introduction to Electrodynamics and having problems to grasp few things.
Anyway, taking into account a problem of dielectric being put between parallel plate capacitor.
There is an E field of capacitor as an external field, and I know inside there is a polarization, dipole per volume P
With the story of induced charges and how dipoles are orienting, I believe I got the right in my mind. What I want to ask firstly, that field E and field P are in opposite direction? I am just asking this for example of parallel place capacitor and dielectric between them?
Now, there is a final field D, which we associate with free charges. And P is associated with the bound charges. And I should consider E fundamental and related to the total charge (free+bound).
Now: $ D=\epsilon_0E + P $
And know constantly in my head is that this should be $-P$. Like $D+p$ should equal to $E$ and also in terms of bound and free charges.
And totally I got it in my mind that $D$ and $E$ are in same direction and $P$ is opposite.
I know question might be dump, but I am losing to understand this properly, read some previous answers here and material on Internet, but still got feeling in my head "I am no exactly sure what is happening here"...